Spring biased well jar



Sept. 28, 1965 R. R. LAWRENCE SPRING BIASED WELL JAR 4 Sheets-Sheet 1 Filed Jan. 29, 1962 ATTO/P/Vfy Sept. 28, 1965 LAWRENCE 3,208,541

SPRING BIASED WELL JAR Filed Jan. 29, 1962 4 Sheets-Sheet 4 7& M

ATTORNEY United States Patent 3,208,541 SPRING BIASED WELL JAR Richard R. Lawrence, 125 McCarty, Houston, Tex. Filed Jan. 29, 1962, Ser. No. 169,375 4 Claims. (Cl. 175299) This invention relates to well jars and more particularly to jarring mechanism which is incorporated in a string of well pipe for use in releasing the string in the event that it should become stuck or to apply an impact to the string when the same has been connected to a lost object or fish which is to be recovered from a well.

The invention is useful for a variety of difierent purposes in the drilling and production of wells, and finds particular application in connection with the carrying out of fishing operations and for the recovering of lost or stuck objects in well bores.

In the drilling and production of oil and gas wells a number of adverse conditions often arise which cause sticking of the drilling string such as the formation of key seats in the wall of the well bore, the caving-in of the formation or the settling of drilling mud or cuttings, which may make it necessary that expensive and time consuming wash-over or fishing operations be carried out before the well can be completed.

For the purpose of aiding in the prevention of sticking of the drilling string and of releasing the same upon the occurrence of such conditions suitable jarring mechanism is frequently incorporated in the string by which a jarring impact may be delivered by manipulation of the string. By the employment of mechanism of this kind, it is often possible to quickly release the string in the event of sticking or to jar loose a broken or disconnected portion of a drill pipe or other object which has become stuck in a well.

The present invention has for an important object the provision of jarring mechanism which may be incorporated in a string of well pipe and which may be used to rotate the string in either direction or to deliver an upward or a downward jarring action on the string as may be desired.

Another object of the invention is to provide jarring mechanism which is constructed to operate with a snapping action to deliver a sudden impact to the string upon the exertion of a predetermined pull or stretching force to the string or upon the exertion of a predetermined downward or compressive force thereon.

A further object of the invention is the provision in well jar mechanism of means whereby the mechanism may be operated with a snapping action to deliver a sudden jarring impact or which may be manipulated to permit an upward or downward bumping action of the mechanism without such snapping action.

Another object of the invention is to provide a well jar of the kind mentioned embodying latching or triggering mechanism by which the jar may be operated to secure a snapping impact and which may be reset by manipulation of the string to repeat such operation.

A further object of the invention is the provision of a well jar which is of strong and rugged construction and which is closed against the entrance of extraneous material into the interior of the jarring mechanism.

The above and other important objects and advantages of the invention will become apparent upon consideration of the following detailed description, reference being had to the accompanying drawings illustrating a preferred embodiment of the invention.

FIGURE 1 is a vertical, central, longitudinal, crosssectional view, on a reduced scale, illustrating a preferred embodiment of the invention, showing somewhat schematically the arrangement of the parts in the centralized 3,208,541 Patented Sept. 28, 1965 or latched condition of the mechanism preparatory to the carrying out of a jarring operation;

FIGURE 2 is a view similar to that of FIGURE 1 showing the relative positions of the parts upon actuation of the mechanism to deliver a downward jarring lmpact;

FIGURE 3 is a view similar to that of FIGURE 1 showing the positions of the parts upon the delivery of an upward impact by the mechanism;

FIGURES 4A, 4B, 4C and 4D are fragmentary, vertical, central, longitudinal, cross-sectional views, on a somewhat enlarged scale, showing details of structure and the arrangement of the parts of the jar in the downward impact delivering posit-ion of the mechanism;

FIGURE 5 is a cross-sectional view taken along the line 5-5 of FIGURE 4A, looking in the direction indicated by the arrows;

FIGURE 6 is a cross-sectional view, taken along the line 66 of FIGURE 4C, looking in the direction indicated by the arrows;

FIGURE 7 is a cross-sectional view, taken along the line 7-7 of FIGURE 4C, looking in the direction indicated by the arrows; and

FIGURE 8 is a fragmentary view partly broken away and partly in cross-section, on a somewhat enlarged scale, showing structural details of the latch or trigger holding mechanism of the invention.

Referring now to the drawings in greater detail, the invention is illustrated herein in connection with its application to a drilling string, or the like, such as is commonly employed in the drilling of oil and gas wells and to which it may be desired to deliver a jarring impact to release the string in the event of sticking of the string in the well bore or to exert a jarring action on a lost object in the bore to which the lower end of the string has been connected.

The jarring mechanism of the invention comprises an outer tubular barrel or main body generally designated 8, which may conveniently be made up of three threadably connected sections, of which the uppermost section 10 constitutes an anvil or impact receiving member, the cen-' tral section 12 being a chamber forming member within which the latching or triggering mechanism of the jar is located, and the lower section 14 being a connector member by which the jar is connected to any type of apparatus which it may be desired to support by the drilling string for rotation and longitudinal movement with the string in the well.

An inner tubular mandrel or stem, generally designated 20 is provided, which is slid-ably extended into the barrel and which is formed with an upper polish rod portion 22 slidably extended through the anvil 10, a notched, latching portion 24 located in the upper portion of the central section 12, a trigger or latch holding portion 26, located in the lower portion of the central section 12, and a lower polish rod portion 28, which is slidably extended into the lower section 14.

Suitable packing, such as the O-ring 30, is located in an internal groove 32 surrounding the polish rod portion within the anvil member 10, and similar packing 34 is located in an internal groove 36 surrounding the polish rod portion 28 in the connector member 14 to form seals between the polish rod portions and sections 10 and 14 to close the ends of an internal annular chamber 38 extending from the seal 30 to the seal 34, and which may be substantially entirely filled with a suitable fluid such as oil.

A connector member 40 is attached to the upper end of the mandrel or stem 20, by which the jar is connected to the lower end of a section of the drilling string above, the lower end of this member having an impact face 42 positioned for engagement with the upper end impact face 44 of the anvil member 10 of the barrel to deliver a downward impact of the barrel upon operation of the jar. The anvil member 10 is also provided with a somewhat enlarged internal counterbore 46 at its upper end from which one or more passageways, such as that shown at 48, lead to the exterior to allow the escape of fluid from the counterbore as the impact member 40 approaches the anvil, whereby any cushioning effect of the downward impact due to the trapping of fluid in the counterbore as the impact member or hammer 40 approaches the anvil is prevented.

The latching portion 24 of the mandrel is of somewhat larger external diameter than the polish rod portion 22, to provide an upwardly facing external shoulder 50 at the upper end of the atching portion, positioned for engagement with the lower end of the anvil 10 to deliver an upward impact to the barrel when the mandrel is moved upwardly therein, and the portion 24 is formed with peripherally spaced, external, longitudinal grooves 52, into which longitudinally spaced, peripherally deepened, external notches 54 open. The notches 54 are preferably formed with rounded bottom wall portions 56 and the side walls 58 diverge outwardly away from the bottom walls, so that the notches are flared outwardly into the grooves 52, as best seen in FIGURE 4B.

The barrel 12 is provided with longitudinally spaced, side openings 60 in which plugs 62 are inserted and secured to the barrel in any suitable manner as by welding, screw threading, or otherwise, and each of these plugs carries a roller 64 rotatably mounted thereon and extending into one of the grooves 52. The rollers 64 are suitably positioned so that they will enter the notches 54 upon rotation of the mandrel clockwise from the position illustrated in FIGURE 5 to hold the mandrel and barrel against relative longitudinal movement. It will be apparent, however, that when the mandrel is in the position of rotation shown in FIGURE 5 the rollers 64 will be out of the notches 54 and located in the grooves 52 to allow the mandrel to move longitudinally in the barrel. Several longitudinally spaced sets of the notches 54 may be provided in the mandrel for each of the grooves 52, if desired.

The holding portion 26 of the mandrel or stem 20 is preferably somewhat smaller in external diameter than the latching portion 24 above, and is provided with peripherally spaced, external, longitudinal grooves 66.

Within the barrel section 12 a narrow stop ring 68 surrounds the mandrel, which ring is secured to the barrel or main body by pins, such as those shown at 70 in FIGURES 4C and 8, extending into peripherally spaced holes in the ring and attached to plugs 72 extending into peripherally spaced holes 74 in the barrel and attached thereto as by means of welding, screw threading, or the like. By this means the stop ring is held against longitudinal movement in the barrel.

Below the ring 68, one or more coil springs 76 surround the mandrel in the barrel, each of which springs is provided with an upper end collar or sleeve portion 78, and a 'lower collar or sleeve portion 80. The upper sleeve or collar 78 of the upper one of the springs 76 abuts against the lower face of the ring 68 and is provided with peripherally spaced, internal rollers 82 rotatably mounted on the barrel in position for rolling contact with the mandrel in the longitudinal grooves 66 to hold the springs against rotation relative to the mandrel.

The lower collar or sleeve 80 is formed with peripherally spaced holes 84, into which pins 86 carried by the barrel are extended. The pins 86 may be attached to the barrel, by means of plugs 88 extending into suitable holes in the barrel and secured thereto as by welding, screw threading, or the like. By this arrangement, it will be apparent that the collars 80 of the springs may be rotated clockwise about the mandrel with the pins 86 removed and the upper collars 78 held against rotation about the mandrel by the rollers 80 in the grooves 66.

When the springs have been thus Wound up to the desired extent the pins 86 are inserted through the holes in the barrel into selected ones of the holes 84 to hold the springs under tension. With the springs thus tensioned and secured to the barrel and mandrel it will be apparent that the springs will exert relative rotational forces on the barrel and mandrel tending to hold the rollers 64 in the notches 54 of the mandrel to releasably latch the mandrel against longitudinal movement in the barrel.

In assembling the jar, constructed as described above, the anvil member 10 is connected to the upper end of the main section 12 of the barrel and the mandrel is inserted upwardly through the main section and anvil and connected at its upper end to the connector or hammer member 40, with the upper polish rod portion 22 of the mandrel slidably extended through the packing 32 and the internal rollers 64 on the barrel extending into the longitudinal grooves 52 of the mandrel. The stop ring 68 is then placed over the mandrel and moved into the barrel to position the ring for attachment to the barrel by the pins 70 by inserting the plugs 72 in the openings 74 and securing the plugs in place on the barrel. With the stop ring thus positioned, one of the springs 76 is placed on the mandrel and moved into the barrel with the rollers 82 on the upper collar portion 78 extending into the grooves 66 of the mandrel, until the upper end of the collar 78 is in engagement with the stop ring 68. The lower collar or sleeve portion 80 of the spring is then rotated clockwise, as viewed from above, to place the spring under a predetermined tension, and the pins 86 attached to the plugs 88 are inserted through the lateral openings of the barrel into the openings 84 of the lower collar which are in registration therewith, to hold the spring under tension. Another such spring 76 is next placed on the mandrel with the rollers 82 thereof extending into the grooves 66, and moved into the barrel until the upper collar 78 thereof is in contact with the lower collar 80 of the previously inserted spring, whereupon the lower collar 80 of the lower spring is turned clockwise, as viewed from above, to place this lower spring under a predetermined tension, and the pins 86 inserted to hold this spring under tension.

With the springs thus positioned to apply relative rotative forces to the barrel and mandrel, tending to urge the rollers 64 into the notches 54 of the mandrel, the lower connector section 14 is placed over the polish rod portion 28 of the mandrel and screwed into the lower end of the main section 12 of the barrel with the polish rod section slidably extended through the packing 34.

When the jar has been thus assembled, the chamber 38, formed between the mandrel and barrel, between the upper and lower packing elements 30 and 34, is filled with a suitable hydraulic fluid such as oil, which may be introduced into the chamber through a suitable opening, not shown, which may be subsequently closed, as by means of a screw plug, to substantially completely fill the chamber.

The jar, thus assembled, may be connected into a drilling string or other well pipe by connecting the lower end of an upper section of such pipe to the upper end of the connector or hammer member 40, and the upper end of a lower section of such pipe or some other device such as a fishing tool to the lower end connector member 14 of the barrel.

In operating the jar, assembled and connected into a drilling or operating string, as described above, the string is lowered in the well to engage the grapple or fishing tool with the object or fish which is to be recovered from the well. The string may then be rotated or otherwise manipulated to connect the grapple to the fish, the barrel 8 and mandrel 20 of the jar being rotative together with the string in either direction.

When the jar is not being operated to deliver an impact, the rollers 64 will ordinarily be in the notches 54 of the mandrel, in which they will be yieldingly held by the tension of the springs 76, thus releasably latching the jar in the position illustrated in FIGURE 1, preparatory to operation of the jar to deliver an impact either upwardly or downwardly on the string. When it is desired to deliver an upward impact on the string, the upward pull on the string may be increased until the tension on the springs 76 is overcome to allow relative rotation of the barrel and mandrel in a direction to cause the rollers 64 to roll out of the notches 54 into the grooves 52, whereupon the mandrel will be suddenly moved upwardly with a snapping action to engage the upper end of the portion 24 of the mandrel with the lower end of the anvil member to deliver an upward impact. After the jar has been operated to exert such an upward impact, the upper pull on the string may be reduced to allow the mandrel to move downwardly in the barrel, whereupon the rollers 64 will again enter the notches 54 to latch the jar preparatory to actuation of the same to deliver another impact.

It will be apparent that because of the outwardly flaring shape of the notches 54, the rollers, in engagement with the sides of the notches, will exert a force tending to impart relative rotation to the barrel and mandrel upon the exertion of a pull on the string sufiicient to overcome the tension of the springs 76, to move the rollers 64 out of the notches into the grooves 52, to permit sudden relative longitudinal movement of the barrel and mandrel.

When it is desired to deliver a downward impact with the jar, the upward pull on the string may be reduced sufficiently to allow the string to exert a downward force on the mandrel sufiicient to overcome the tension of the springs 76, whereupon the rollers 64 will move out of the notches 54 into the grooves 52, to allow the mandrel to move suddenly downwardly in the barrel to engage the lower end of the connector or hammer member 40 with the upper end of the anvil member 10. When the downward impact has been thus delivered, the mandrel may again be moved upwardly by an upper pull on the string to allow the rollers 64 to again enter the notches 54 to reset the latching mechanism preparatory to further jarring operation.

The longitudinal force which must be exerted to release the latching mechanism of the jar may, of course, be adjusted as desired by adjusting the tension of the springs 76, so that a predetermined impact may be delivered by the jar. The amount of rotative force or torque required to release the latching mechanism may also be varied by increasing the number of the springs 76 which are used in the jar, as many such springs being added as may be desired.

It will also be apparent that the jar may be operated by applying a counterclockwise rotative force to the mandrel to move the rollers 64 out of the notches into the grooves 52, so that the jar may be operated by upward or downward movement of the string, without the snapping action which takes place when the latching mechanism is released solely by a longitudinal force exerted on the mandrel.

In the event that it should be desired to increase the impact delivered by the jar during the operation of the apparatus, this may be accomplished without removing the jar from the well by exerting a rotative force on the string in the latching direction (clockwise as viewed from above in the apparatus as illustrated in FIGURE 5) to increase the amount of longitudinal force which must be applied to cause the latching mechanism to release, so that a greater impact will be obtained.

The jarring mechanism for the invention may also be applied to other kinds of well apparatus, such as pump rods, or the like, in which case the inner part or mandrel may be made solid rather than tubular, under circumstances in which it is unnecessary to provide for the circulation of fluid through the string.

It will thus be seen that the invention provides jarring mechanism which permits rotation of a drilling string in either direction, and which embodies latching mechanism which may be released solely by the exertion of a longitudinal force on the string to cause the jar to deliver an impact by a sudden snapping action, or which may be released by the exertion of a rotative force to allow the jar to be extended or retracted by longitudinal manipulation of the string.

The invention is disclosed herein in connection with a certain specific embodiment of the same, but it will be understood that this is intended by way of example only, and that various changes can be made in the construction and arrangement of the parts within the spirit of the invention.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

1. In a well jar inner and outer telescopingly arranged tubular parts movable longitudinally relative to each other, means for connecting one of said parts to an operating string, means for connecting the other of said parts to an object stuck in a well bore, coacting impact faces on the parts positioned for contact when the parts reach the limit of their relative longitudinal movement in one direction, said inner part having an external longitudinal groove and a laterally extending U-shaped notch opening into the groove and formed with curved outwardly flaring side walls, roller means rotatably mounted on the outer part extending into the groove and engageable with the inner part to hold the parts against relative rotation, and positioned for movement into said notch upon relative rotation of the parts in one direction when the parts are in a predetermined relative longitudinal position with said faces out of contact to hold the parts against relative longitudinal movement, and for rolling movement in contact with one of said side walls out of said notch to impart relative rotation to the parts in the other direction upon the exertion of a predetermined force to the parts tending to move the parts longitudinally relative to each other.

2. In a well jar inner and outer telescopingly arranged tubular parts movable longitudinally relative to each other, means for connecting one of said parts to an operating string, means for connecting the other of said parts to an object stuck in a well bore, coacting impact faces on the parts positioned for contact when the parts reach the limit of their relative longitudinal movement in one direction, said inner part having an external longitudinal groove and a laterally extending U-shaped notch opening into the groove and formed with curved, outwardly flaring side walls, roller means rotatably mounted on the outer part extending into the groove and engageable with the inner part to hold the parts against relative rotation, and positioned for movement into said notch upon relative rotation of the parts in one direction when the parts are in a predetermined relative longitudinal position with said faces out of contact to hold the parts against relative longitudinal movement, and for rolling movement along one of said side walls out of said notch to impart relative rotation to the parts in the other direction upon the exertion of a force to the parts tending to move the parts longitudinally relative to each other in either direction and yieldable means positioned for coaction with the parts to yieldingly resist relative rotation of the parts in said other direction.

3. In a well jar inner and outer telescopingly arranged tubular parts movable longitudinally relative to each other, means for connecting one of said parts to an operating string, means for connecting the other part to an object stuck in a well bore, coacting impact faces on the parts positioned for contact when the parts reach the limits of their relative longitudinal movement in either direction, said inner part having an external longitudinal groove and a laterally extending notch opening to the groove, and roller means on the outer part extending into and rotatably engageable with the inner part in the groove in position to enter the notch upon relative rotation of the parts in one direction when the parts are in one position of relative longitudinal movement between said limits to hold the parts against relative longitudinal movement, yieldable means positioned for coaction with the parts to yieldingly resist relative rotational movement of the parts in the other direction, the side walls of said notch being shaped for coaction with said roller means to apply a force to the parts tending to rotate the parts in said other direction upon the exertion of a force on the parts tending to move the parts longitudinally relative to each other away from said one position.

4. In a well jar inner and outer telescopingly arranged tubular parts movable longitudinally relative to each other, means for connecting one of said parts to an operating string, means for connecting the other part to an object stuck in a well bore, coacting impact faces on the parts positioned for contact when the parts reach the limits of their relative longitudinal movement in either direction, said inner part having an external longitudinal groove and a laterally extending notch opening into the groove, and roller means on the outer part extending into and rotatably engageable with the inner part in the groove in position to enter the notch upon relative rotation of the parts in one direction when the parts are in one position of relative longitudinal movement between said limits to hold the parts against relative longitudinal movement, yieldable means positioned for coaction with the parts to yieldingly resist relative rotational movement of the parts in the other direction, said notch having a curved bottom wall conforming to the shape of and engageable with the periphery of said roller means when the roller means reaches the limit of its inward movement in the notch and outwardly flaring side walls, merging at their outer ends with one side wall of said groove for coaction with said roller means to apply a force to the parts tending to rotate the parts in said other direction to cause a sudden release of the roller means from the notch upon the exertion of a predetermined force on the parts tending to move the parts longitudinally relative to each other away from said one position.

References Cited by the Examiner UNITED STATES PATENTS 1,672,321 6/ 28 Kammerdiner 175299 1,899,438 2/33 Grant 175299 2,056,496 10/36 White 175304 2,101,968 12/37 Wickersham 175-304 2,474,459 6/49 Beck 175-304 2,550,142 4/51 Dumble 175304 2,562,321 7/51 Lowe 175-304 BENJAMIN HERSH, Primary Examiner.

CHARLES E. OCONNELL, Examiner. 

1. IN A WELL JAR INNER AND OUTER TELESCOPINGLY ARRANGED TUBULAR PARTS MOVABLE LONGITUDINALLY RELATIVE TO EACH OTHER, MEANS FOR CONNECTING ONE OF SAID PARTS TO AN OPERATING STRING, MEANS FOR CONNECTING THE OTHER OF SAID PARTS TO AN OBJECT STUCK IN A WELL BORE, COACTING IMPART FACES ON THE PARTS POSITIONED FOR CONTACT WHEN THE PARTS REACH THE LIMIT OF THEIR RELATIVE LONGITUDINAL MOVEMENT IN ONE DIRECTION, SAID INNER PART HAVING AN EXTERNAL LONGITUDINAL GROOVE AND A LATERAL EXTENDING U-SHAPED NOTCH OPENING INTO THE GROOVE AND FORMED WITH CURVED OUTWARDLY FLARING SIDE WALLS, ROLLER MEANS ROTATABLY MOUNTED ON THE OUTER PART EXTENDING INTO THE GROOVE AND ENGAGEABLE WITH THE INNER PART OF HOLD THE PARTS AGAINST RELATIVE ROTATION, AND POSITIONED FOR MOVEMENT INTO SAID NOTCH UPON RELATIVE ROTATION OF THE PARTS IN ONE DIRECTION WHEN THE PARTS ARE IN A PREDETERMINED RELATIVE LONGITUDINAL POSITION WITH SAID FACES OUT OF CONTACT TO HOLD THE PARTS AGAINST RELATIVE LONGITUDINAL MOVEMENT, AND FOR ROLLING MOVEMENT IN CONTACT WITH ONE OF SAID SIDE WALLS OUT OF SAID NOTCH TO IMPART RELATIVE ROTATION TO THE PARTS IN THE OTHER DIRECTION UPON THE EXERTION OF A PREDETERMINED FORCE TO THE PARTS TENDING TO MOVE THE PARTS LONGITUDINALLY RELATIVE TO EACH OTHER. 